Background: Delayed healing of diabetic wounds has been well-documented. Currently, the use of platelet-rich plasma (PRP) has attracted great attention in many medical fields including wound healing. Aim: Histological, immunohistochemical and ultrastructural evaluation of the effect of PRP on wound healing in the tongue of normal and Streptozotocin-induced diabetic albino rats. Methodology: A total number of 108 adult male albino rats with average weight 200gm, were used in the study. The animals were classified into two main groups: non-diabetic and diabetic groups. Each group was further divided into three subgroups: non- treated wound, PRP-treatment before wound, and PRP-treatment after wound. Tongue specimens were dissected on postoperative days 1, 3, and 7. The specimens were examined histologically by H&E, immunohistochemically by p63 and vimentin, and ultra-structurally by TEM. Results:  The most accelerated wound healing was revealed in the subgroups treated with PRP before the wound, whether non-diabetic or diabetic, which occurred very early at the 3rd day postoperative in both cases. While complete wound healing was revealed at the 7th day postoperative in both the non-diabetic and diabetic subgroups treated with PRP after the wound, which was like the non-diabetic control subgroup. Whilst, the diabetic non-treated subgroup only showed partial wound healing at the 7th day postoperative. Conclusion: A single injection of PRP could be used as a prophylactic to prevent expected impaired wound healing in diabetic oral mucosal wounds and to enhance wound healing in non-diabetic wounds. PRP could be used as a therapeutic to enhance wound healing in diabetic and non-diabetic oral mucosal wounds. Key Words: platelet rich plasma, wound healing, diabetes, rat, tongue, p63, vimentin, TEM BACKGROUND: Delayed healing of diabetic wounds has been well-documented. At present, the use of platelet-rich plasma (PRP) has attracted great attention in many medical fields including wound healing. AIM: Histological, immunohistochemical, and ultrastructural evaluation of the effect of PRP on wound healing in the tongue of normal and streptozotocin-induced diabetic albino rats. METHODOLOGY: A total number of 108 adult male albino rats with average weight 200 g were used in the study. The animals were classified into two main groups: Non-diabetic and diabetic groups. Each group was further divided into three subgroups: Non-treated wound, PRP-treatment before wound, and PRP-treatment after wound. Tongue specimens were dissected on post-operative days 1, 3, and 7. The specimens were examined histologically by H&E, immunohistochemically by p63 and vimentin, and ultrastructurally by TEM. RESULTS: The most accelerated wound healing was revealed in the subgroups treated with PRP before the wound, whether non-diabetic or diabetic, which occurred very early at the 3rd day post-operative in both cases. While complete wound healing was revealed at the 7th day post-operative in both the non-diabetic and diabetic subgroups treated with PRP after the wound, which was like the non-diabetic control subgroup. While, the diabetic non-treated subgroup only showed partial wound healing at the 7th day post-operative. CONCLUSION: A single injection of PRP could be used as a prophylactic to prevent expected impaired wound healing in diabetic oral mucosal wounds and to enhance wound healing in non-diabetic wounds. PRP could be used as a therapeutic to enhance wound healing in diabetic and non-diabetic oral mucosal wounds.

Background: Diabetes Mellitus causes many systemic and oral complications including impaired wound healing. Recently, platelet-rich plasma (PRP) treatment to utilize a patient's own platelets and growth factors to improve healing at the site of injury has been used extensively. Objective: Evaluation of the effect of PRP on tongue wound healing in normal and Streptozotocin-induced diabetic albino rats by H&E and Masson's trichrome histological stains and by TEM ultrastructural examination. Methodology: A total number of 108 adult male albino rats with average weight 200gm, were used in the experiment. The rats were classified into two main groups: non-diabetic and diabetic groups. Each group was further divided into three subgroups: non-treated wound, PRP-treatment before wound, and PRP-treatment after wound. Tongue specimens were dissected on postoperative days 3, 7, and 10. The specimens were examined histologically by H&E and MT, and ultrastructurally by TEM. Results: The most rapid wound healing was revealed in the non-diabetic and diabetic subgroups treated with PRP before the wound, which occurred very early at the 3 rd day postoperative. While complete wound healing was revealed at the 7 th day postoperative in both the non-diabetic and diabetic subgroups treated with PRP after the wound, which was like the non-diabetic control subgroup. Whilst, the diabetic non-treated subgroup was the last to show wound healing which took place at the 10 th day postoperative. Conclusion: PRP could be applied before or after wounding occurs, to prevent impaired wound healing and to enhance wound healing in diabetic and non-diabetic oral mucosal wounds.

Background: Arsenic was used in medicine, cosmetics industry, and agriculture. Nowadays, using arsenic in endodontics has greatly declined due to the severe damage to vital pulp tissue, and periodontium. Folic acid is one of the forms of vitamin B9 and it possesses a significant antioxidant effect. Zinc performs proapoptotic, anti-inflammatory and protective antioxidant activities.Objective: Evaluation of effect of folic acid and zinc chloride (ZnCl 2 ) on arsenic treated pulp tissue of rats.Methodology: Twenty-five rats were divided into five groups; each group consisted of 5 rats: Group (1); served as a control without any treatments. Experimental groups (2,3 and 4); arsenic treated group, folic acid treating in arsenic treated group and ZnCl 2 treating in arsenic treated group sequentially. After 24 hours from the last dose, specimens were taken and processed for H&E, and immunohistochemical stains: Nrf2 and TNF-α, morphometric analysis and statistical analysis.Results: Groups 1,3 and 4 showed mostly Nrf2 negative immunoreactivity in odontoblastic cell layer and faint Nrf2 immunoreactivity in pulp tissue. But group 2 had strong Nrf2 positive immunoreactivity in cytoplasm and nucleus of disorganized odontoblastic cell layer and in pulp tissue. Groups 1 and 3 showed very weak TNF-α immunoreactivity in pulp tissue. But group 2 had very strong positive TNF-α immunoreactivity in pulp tissue. While group 4 showed TNF-α negative immunoreactivity in pulp tissue. Conclusion:As 2 O 3 has a toxic effect on pulp tissue through increasing the reactive oxygen species. ZnCl 2 has a powerful detoxification effect more than folic acid in arsenic treated pulp tissue.